Portable tool attachment



@ct. M, 11933 E. HENRY 3,929,585

PORTABLE TOOL- ATTACHMENT Filed March 17, 1931 Patented Oct. 10, 1933 1,929,585 PORTABLE TOOL ATTACHMENT Eugene Henry,

American Car and Detroit, Mich, assignor to V Foundry Motors Company,

New York, N. Y., a corporation of Delaware Application March 17, 1931. Serial No. 523,288 1 Claim. (01. '17-55) This invention relates to portable electric tools for drilling or reaming and has particular reference to anattachment for such tools for gauging the depth of a hole being drilled or reamed whereby to limit the penetration of the drill or reamer bit.

One object of this invention is. the provision of an attachment for portable tools of the character specified which comprises an adjustable gauging element adapted to be thrown into and out of operative relation with respect to a tool bit. 7

Another object of this invention is the provision of an attachment for portable tools for drilling or reamingwhich, includes a plurality of adjustable gauging elements or stops adapted to be moved into and out of operative relation to a tool bit and to be retained in either inoperative or opcrative relation with respect to said bit.

A further object of this invention is the provision of an attachment for portable electric tools of the character described which comprises a plurality of adjustable multi-part gauging elements hingedly connected to a bracket, the arrangement being such that any one of the gauging elements may be thrown into operative relation with respect to a tool bit for limiting the penetration of the latter whereby an opening of predetermined depth may be formed in a piece of work.

Other objects and advantages of this invention will be apparent from the following description taken in conjunction with the accompanying drawing in which:

Figure 1 is a perspective view of a portable electric tool having the present invention applied thereto, and

Fig. 2 is a front elevation of the attachment,

a part of the latter being shown in section.

The drawing shows the invention applied to a conventional portable electric tool such as a drill A for limiting the operation of the drill bit 2. The invention comprises a bracket or mounting B curved to the form of the body portion 4 of the tool and secured thereto by fasteners 6 which extend 5 through the enlarged head portion 8 of said bracket. The bracket is substantially T-shaped in plan, the head portion 8 of the bracket forming the head of the T and providing an enlarged attaching portion for restraining the bracket 5 against shifting on the tool. The head portion of the bracket is of arcuate formation to snugly fit the body portion 4 of the tool. The bracket is arranged longitudinally of the tool and the body portion or base 10 of the bracket is provided at its end with parallel spaced hinge lugs 12 which support a pivot pin 14 on which latter are mounted a plurality of multi-part stop members or gauges 18. The bracket, as clearly shown in the drawing, is so positioned on the tool, and the stop members are so arranged that they may be retained in an inoperative position relative to the bit 2, or may be swung on the pivot so as to lie adjacent the bit 2 to limit penetration of the latter into work, as will be hereinafter more specifically described. These stops 18 comprise T- shaped elements having heads 20 through which the before-mentioned pin 14 extends whereby said stops are pivotally connected to the bracket B. The stops also include stem portions 22 which are externally threaded to adjustably support internally threaded sleeves or extension pieces 24. Secured to the stem portions 22 of the stops are look nuts 26 for retaining the sleeves 24 in any predetermined adjusted position relative to the stems 22. Inasmuch as the tool of the present invention may often be used for drilling or reaming finished surfaces, the sleeves 24 are provided with pads 27 at their free ends formed of resilient or other shock absorbing material which will not mar finished surfaces; the pads being removably connected tothe ends of the sleeves by having threaded attaching portions 28 which engage the internal threads of the sleeves 24 as shown clearly in Fig. 2.

The present invention includes means for restraining the stop elements against free movement on the pin 16, and to this end friction elements 30 in the form of springs are mounted on the pin 16 between the ears 12 and the contiguous portions of the heads 20 of the stop elements. To permit free independent movement of the stop elements relative to each other, a spacer 32 is mounted on the pin 16 and between the head portions 20 of the adjacent stop elements. It will be obvious that the springs 30 urge the stop elements into contact with the spacer 32 and retain the said stop elements in frictional contact with said spacer.

In use, the sleeves forming parts of the stop elements, are adjusted to a desired setting on the stems 22 and it is apparent that the operation of the bit 2 is limited by the particular stop which may be arranged adjacent said bit. It will be apparent that either stop or gauge may be easily and quickly placed into operative relation with respect 195 to the bit by swinging it on the hinge pin 14. The resilient friction elements 30 serve to restrain the stop elements against accidental shifting on the pivot pin as will be obvious.

It is believed that the construction and operation of the present invention will be fully apparent to those skilled in the art. The drawing discloses one embodiment of the invention, but it is to be understood they are for illustrative purposes only and the invention is susceptible of various modifications within the scope of the appended claim without departing from the spirit of the invention.

What is claimed is:

A depth gauge for hand drills comprising a T 

